Impact of sex on the efficacy and safety of panitumumab plus fluorouracil and folinic acid versus fluorouracil and folinic acid alone as maintenance therapy in RAS WT metastatic colorectal cancer (mCRC). Subgroup analysis of the PanaMa-study (AIO-KRK-0212).

BACKGROUND: Clinical trials in metastatic colorectal cancer (mCRC) are usually conducted irrespective of sex. Sex-associated differences relating to safety and efficacy in the treatment of mCRC, however, are gaining interest. METHODS: PanaMa investigated the efficacy of panitumumab (Pmab) plus fluorouracil and folinic acid (FU/FA) versus FU/FA alone after induction therapy with six cycles of FU/FA and oxaliplatin plus Pmab in patients with RAS wild-type mCRC. In this post hoc analysis, the study population was stratified for sex. Evaluated efficacy endpoints during maintenance treatment were progression-free survival (PFS, primary endpoint of the trial), overall survival (OS) and objective response rate during maintenance therapy. Safety endpoints were rates of any grade and grade 3/4 adverse events during maintenance therapy. RESULTS: In total, 165 male and 83 female patients were randomized and treated. Male and female patients showed numerically better objective response rates with Pmab, without reaching statistical significance. Male patients derived a significant benefit from the addition of Pmab to maintenance treatment with regard to PFS [hazard ratio (HR) 0.63; 95% confidence interval (CI) 0.45-0.88; P = 0.006] that was not observed in female patients (HR 0.85; 95% CI 0.53-1.35; P = 0.491). The better PFS for male patients treated with Pmab did not translate into improved OS (HR 0.85; 95% CI 0.55-1.30; P = 0.452). Female patients showed numerically improved OS when treated with Pmab. There was no difference in the total of grade ≥3 adverse events during maintenance regarding sex (P = 0.791). Female patients, however, had a higher rate of any grade nausea, diarrhea and stomatitis. CONCLUSIONS: In the PanaMa trial, the addition of Pmab to maintenance treatment of RAS wild-type mCRC with FU/FA improved the outcome in terms of the primary endpoint (PFS) particularly in male patients. Female patients did not show the same benefit while experiencing higher rates of adverse events. Our results support the development of sex-specific protocols.

Study protocol of the FIRE-8 (AIO-KRK/YMO-0519) trial: a prospective, randomized, open-label, multicenter phase II trial investigating the efficacy of trifluridine/tipiracil plus panitumumab versus trifluridine/tipiracil plus bevacizumab as first-line treatment in patients with metastatic colorectal cancer.

BACKGROUND: Initial systemic therapy for patients with metastatic colorectal cancer (mCRC) is usually based on two- or three-drug chemotherapy regimens with fluoropyrimidine (5-fluorouracil (5-FU) or capecitabine), oxaliplatin and/or irinotecan, combined with either anti-VEGF (bevacizumab) or, for RAS wild-type (WT) tumors, anti-EGFR antibodies (panitumumab or cetuximab). Recommendations for patients who are not eligible for intensive combination therapies are limited and include fluoropyrimidine plus bevacizumab or single agent anti-EGFR antibody treatment. The use of a monochemotherapy concept of trifluridine/ tipiracil in combination with monoclonal antibodies is not approved for first-line therapy, yet. Results from the phase II TASCO trial evaluating trifluridine/ tipiracil plus bevacicumab in first-line treatment of mCRC patients and from the phase I/II APOLLON trial investigating trifluridine/ tipiracil plus panitumumab in pre-treated mCRC patients suggest favourable activity and tolerability of these new therapeutic approaches. METHODS: FIRE-8 ( NCT05007132 ) is a prospective, randomized, open-label, multicenter phase II study which aims to evaluate the efficacy of first-line treatment with trifluridine/tipiracil (35 mg/m2 body surface area (BSA), orally twice daily on days 1-5 and 8-12, q28 days) plus either the anti-EGFR antibody panitumumab (6 mg/kg body weight, intravenously on day 1 and 15, q28 days) [arm A] or (as control arm) the anti-VEGF antibody bevacizumab (5 mg/kg body weight, intravenously on day 1 and 15, q28 days) [arm B] in RAS WT mCRC patients. The primary objective is to demonstrate an improved objective response rate (ORR) according to RECIST 1.1 from 30% (control arm) to 55% with panitumumab. With a power of 80% and a two-sided significance level of 0.05, 138 evaluable patients are needed. Given an estimated drop-out rate of 10%, 153 patients will be enrolled. DISCUSSION: To the best of our knowledge, this is the first phase II trial to evaluate the efficacy of trifluridine/tipiracil plus panitumumab in first-line treatment of RAS WT mCRC patients. The administration of anti-EGFR antibodies rather than anti-VEGF antibodies in combination with trifluridine/tipiracil may result in an increased initial efficacy. TRIAL REGISTRATION: EU Clinical Trials Register (EudraCT) 2019-004223-20 . Registered October 22, 2019, ClinicalTrials.gov NCT05007132 . Registered on August 12, 2021.

Left-sided primary tumors are associated with favorable prognosis in patients with KRAS codon 12/13 wild-type metastatic colorectal cancer treated with cetuximab plus chemotherapy: an analysis of the AIO KRK-0104 trial.

PURPOSE: AIO KRK-0104 investigated first-line therapy of metastatic colorectal cancer (mCRC) with cetuximab, capecitabine and irinotecan versus cetuximab, capecitabine and oxaliplatin. This analysis investigated the impact of primary tumor location on outcome of patients. PATIENTS AND METHODS: Left-sided primary tumors were defined as tumors from rectum to left flexure, while tumors in the remaining colon were regarded right sided. Overall survival (OS), progression-free survival (PFS) and response rate were correlated with primary tumor location. A Cox regression model was used to evaluate interaction between primary tumor location and KRAS mutation. RESULTS: Of 146 patients of the AIO KRK-0104 trial, 100 patients presented left-sided (of those 68 KRAS codon 12/13 wild-type) and 46 patients right-sided primary tumors (of those 27 KRAS codon 12/13 wild-type). Left-sided tumors were associated with significantly longer OS (p = 0.016, HR = 0.63) and PFS (p = 0.02, HR = 0.67) as compared to right-sided tumors. These effects were present in the KRAS codon 12/13 wild-type population (HR OS: 0.42; HR PFS: 0.54), while no impact of primary tumor location was evident in patients with KRAS codon 12/13 mutant tumors (HR OS: 1.3; HR PFS: 1.01). A significant interaction of KRAS status and primary tumor location concerning OS and PFS was observed. CONCLUSION: Our findings suggest that primary tumor location and KRAS codon 12/13 mutational status interact on the outcome of patients with mCRC receiving cetuximab-based first-line therapy. Left-sided primary tumor location might be a predictor of cetuximab efficacy.

Weekly docetaxel monotherapy for advanced gastric or esophagogastric junction cancer. Results of a phase II study in elderly patients or patients with impaired performance status.

BACKGROUND: Three-weekly docetaxel is active in patients with advanced esophagogastric cancer but myelosuppression may make this schedule unsuitable for some patient groups such as elderly, pretreated, or poor performance status patients. PATIENTS AND METHODS: Eligible patients were chemonaive with Karnofsky index < or =70% and/or had received prior platinum-based chemotherapy. Docetaxel 35 mg/m(2) was administered on days 1, 8, 15, 22, 29, and 36 of a 49-day cycle. The primary endpoint was disease stabilization rate. RESULTS: Of 46 patients (median age, 68.5 years; 47% > or =70 years) included, 87% had Karnofsky index < or =70 and 50% had prior treatment. The safety profile was acceptable. Principal grade 3/4 toxicities were leukopenia (9%) and fatigue (14%). Fifteen patients experienced no progression for > or =100 days (disease stabilization rate: 36%). Overall response rate was 9%; median overall survival was 7.0 months. CONCLUSIONS: Weekly docetaxel was well tolerated and achieved disease stabilization in one-third of difficult-to-treat patients.